title: Statistical assessment of normal mitral annular geometry using automated three-dimensional echocardiographic analysis.
abstract: BACKGROUND
  The basis of mitral annuloplasty ring design has progressed from qualitative surgical intuition to experimental and theoretical analysis of annular geometry with quantitative imaging techniques. In this work, we present an automated three-dimensional (3D) echocardiographic image analysis method that can be used to statistically assess variability in normal mitral annular geometry to support advancement in annuloplasty ring design.
  
  
  METHODS
  Three-dimensional patient-specific models of the mitral annulus were automatically generated from 3D echocardiographic images acquired from subjects with normal mitral valve structure and function. Geometric annular measurements including annular circumference, annular height, septolateral diameter, intercommissural width, and the annular height to intercommissural width ratio were automatically calculated. A mean 3D annular contour was computed, and principal component analysis was used to evaluate variability in normal annular shape.
  
  
  RESULTS
  The following mean ± standard deviations were obtained from 3D echocardiographic image analysis: annular circumference, 107.0 ± 14.6 mm; annular height, 7.6 ± 2.8 mm; septolateral diameter, 28.5 ± 3.7 mm; intercommissural width, 33.0 ± 5.3 mm; and annular height to intercommissural width ratio, 22.7% ± 6.9%. Principal component analysis indicated that shape variability was primarily related to overall annular size, with more subtle variation in the skewness and height of the anterior annular peak, independent of annular diameter.
  
  
  CONCLUSIONS
  Patient-specific 3D echocardiographic-based modeling of the human mitral valve enables statistical analysis of physiologically normal mitral annular geometry. The tool can potentially lead to the development of a new generation of annuloplasty rings that restore the diseased mitral valve annulus back to a truly normal geometry.
authors.affiliation: Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania; Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Alison M
authors.initials: AM
authors.lastname: Pouch
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Vergnat
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jeremy R
authors.initials: JR
authors.lastname: McGarvey
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Ferrari
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Benjamin M
authors.initials: BM
authors.lastname: Jackson
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Chandra M
authors.initials: CM
authors.lastname: Sehgal
authors.affiliation: Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Yushkevich
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Gorman
authors.affiliation: Gorman Cardiovascular Research Group, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Surgery, University of Pennsylvania, Philadelphia, Pennsylvania. Electronic address: gormanj@uphs.upenn.edu.
authors.forename: Joseph H
authors.initials: JH
authors.lastname: Gorman
mesh_terms: D003198:Computer Simulation; D019560:Echocardiography, Three-Dimensional / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008943:Mitral Valve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging* / Q000601:surgery; D058386:Mitral Valve Annuloplasty / Q000379:methods; D008953:Models, Anatomic; D012016:Reference Values; D013223:Statistics as Topic
keywords: 35